Suggest Remedy For Stomach Ailments

40 year old male, 6'3" 280#, just started working out on tread mill 6 weeks ago, walking at 3 mph for 40 min and a total of 2 miles. stopped walking for a week because i had wisdom teeth removed 4 weeks ago, was on hydrocod-apap 5-500mg tab and clindamycin 150mg (40 tabs) soft foods for a week, two weeks later, stools still soft (once or twice Diarrea) still walking and cut food intake, but then took double vitamins, a,b,c,d,e, all at the sametime for 4 days and now my stomach is aching dual pain stool is good brown color and urine is normal yellow, whats wrong?